Analysis of corrected Cerenkov emission during electron radiotherapy by Monte Carlo method
Analysis of corrected Cerenkov emission during electron radiotherapy by Monte Carlo method
复制标题
蒙特卡罗法分析电子放射治疗中修正切伦科夫发射
DOI：
10.1016/j.apradiso.2020.109481
复制
发表时间：
2021-01-05
影响因子：
1.6
通讯作者：
Zhang, Chunmin
中科院分区：
文献类型：
--
作者：
Li, Yi;Liu, Hongjun;Zhang, Chunmin
电子放射治疗中的切伦科夫辐射已成为临床放射治疗的一种新的剂量评估方法，并可通过标准的商用相机进行成像。本文旨在研究蒙特卡罗(MC)方法在电子放射治疗中修正切伦科夫发射法的准确性。用Gamos MC软件模拟电子治疗的物理过程，计算水模中的剂量和切伦科夫光子分布。与电离室和二极管测量相比，MC模拟剂量曲线的百分深度剂量(PDD)曲线误差小于1%，交叉线分布曲线误差小于2.2%，符合临床标准。与电离室剂量测量相比，MC模拟的切伦科夫分布的交叉线分布误差小于2%，符合临床标准。然而，切伦科夫PDD曲线往往高估了积累区的剂量，低估了剩余衰减区的剂量。在切伦科夫分布深度增加到2~3 mm后，剩余衰减区的偏差在1%以内，符合临床标准。因此，校正的切伦科夫发射可用于评估电子放射治疗中的PDD精度和交叉线轮廓精度。
Cerenkov emission during electron radiotherapy had been emerging as a new dose assessment approach for clinical radiotherapy and could be imaged through a standard commercial camera. The purpose of this work aimed to study the accuracy of corrected Cerenkov emission method during electron radiotherapy by Monte Carlo (MC) method. GAMOS MC software was used to model the physics of electron therapy and calculated dose and Cerenkov photon distribution in water phantom. Compared to ionization chamber and diode measurement, MC simulated dose discrepancy was less than 1% in percentage depth dose (PDD) curves and less than.2% in crossline profile curves, which was acceptable for clinical criterion. Compared to ionization chamber dose measurement, MC simulated Cerenkov discrepancy was less than 2% in crossline profile distribution, which was acceptable for clinical criterion. However, the Cerenkov PDD curves tended to overestimate the dose at the build-up region and underestimate the dose at the remaining attenuation region. After increasing the Cerenkov distribution depth to 2-3 mm, the discrepancy became well within 1% at the remaining attenuation region, which was acceptable for clinical criterion. Therefore, corrected Cerenkov emission could be used to assess PDD accuracy and crossline profile accuracy during electron radiotherapy.